i-line bandpass filter
Features of Asahi filters1)Durable and stable performance with Ion Assisted Deposition. 2)NOT using epoxy glues, avoiding from degradation of performance. 3)High throughput to the photomask with our Photolithography Filters. 4)Any CWL, FWHM and size are precisely available according to your needs. 5)Excellent spectral uniformity across the substrate surface.

Mercury Lamp has several emission lines with great light intensity, and especially i-line (365nm) is the most famous wavelength for photolithography. The i-line bandpass filter for photolithography needs to transmit the monochromatic wavelength, and should be durable and stable to achieve the optimum resolution.

Cold mirror
Asahi cold mirrors are designed to have long, flat and more than 90% transmission in VIS-NIR range to eliminate unwanted light before the light goes through the i-line bandpass filter, and also reflects more than 90% in UV range, which results in the highest throughput for your exposure process. The Asahi cold mirror is also made by IAD to assure durability under the high power mercury lamp. Maximum size of dia.380mm still keeps its excellent uniformity.

Photolithography Filter
Custom Filter